断层影响下隧道喷锚支护效果的数值模拟

Numerical Simulation on the Bolt-shotcrete Support Effect of Cave Tunnel Affected by Fault

喷锚支护是以喷射混凝土、锚杆支护为主要手段,保证围岩稳定的隧道施工方法,其参数设计是维护隧道围岩结构稳定性的关键。结合大华岭隧道及F1断层的结构特点,根据隧址区断层实际走向、断层面产状与隧道轴线不同夹角,采用半经验半理论方法,设计F1断层段锚杆支护参数及混凝土喷射厚度,利用岩土与隧道分析软件MIDAS/GTS对断层影响下的隧道喷锚支护效果进行数值模拟,分析了特定施工段支护前后沉降对比及位移量,讨论了围岩和支护体系的结构状态及工程效果。结果表明,合理选择喷锚支护设计参数可以有效地限制围岩位移,维护围岩的稳定性。该方法可为同类隧道锚杆支护设计、施工和研究提供有益借鉴。

The bolt-shotcrete support is adopted to ensure the stability of wall rock by spraying the cement concrete and fixing the anchor rod.The design of the supporting parameters is the key figure on the stability of wall rock.Combining with Dahualing cave tunnel and the structural features of fault F1,and according to the fault crush belts＇ actual trend,occurrence and different included angle of the cave tunnel axis＇ in Dahualing tunnel,the rock-bolt supporting parameters and the thickness of cement concrete of the fault belt are designed by adopting the semi-empirical and semi-theoretical method.The effect of spraying anchor protection supporting of cave tunnel affected by the fault crush belts is numerically analyzed by using the software MIDAS/GTS.And the contrast analysis of sedimentation and the displacement of certain construction site are made before and after the support.After then,the structure condition and the engineering effect of the surrounding rock and support are discussed.The results show that the reasonable supporting parameters can effectively control the displacement of wall rock and protect its stability.This analysis method can be used as a reference for the design,construction and research of bolt support for similar tunnels.